THE third Toyota Prius was built between 2009 and 2015 and looked very similar to the model it replaced.

But under the skin were a number of major improvements that made it an expensive but realistic alternative to low emission diesels.

It's still a hybrid of course, with a 98bhp 1.8-litre petrol engine mated to a 36bhp electric motor and driving the front wheels through a continuously variable (CVT) automatic gearbox.

The combination delivers good performance when working in tandem, covering the 0-60 sprint in 10.4 seconds. Yet the government average consumption is 72 miles per gallon, with emissions of just 89 grammes per kilometre of carbon dioxide.

That equates to a real driving average of about 50-55mpg with a light right foot, so it's right up there with the diesels.

And as long as there's power in the lithium-ion batteries, which are charged by the engine and by regenerative braking, it will cover about a mile on electric power alone, as long as you keep a very light foot on the accelerator.

As soon as the electric power drops below a certain point, the petrol engine starts seamlessly and begins to charge the batteries again as you drive.

In normal driving around town or on the motorway, the Prius feels just like a normal CVT automatic. The engine sometimes holds higher revs than you might expect, but it is smooth and refined so never too noisy.

From 2012 a more expensive plug-in Prius was added, which only improves on what was already very good, and gives a pure electric range of about 15 miles, with speeds up to about 50 miles an hour.

That means for many people, all local journeys are going to be covered for next to no cost if the car is plugged into the mains every night. A full charge takes about an hour and a half.

Emissions are lower too at an average of 49g/km CO2, and best economy is claimed to be 134.5mpg!

The steering is well-weighted and meaty, but there isn't much road feel. However, the car corners well and also copes admirably with rough and potholed surfaces.

Front seats are supportive and comfortable, and there is also plenty of rear passenger space plus a decent boot.

The dash is dominated by a large screen giving the battery and power situation, and equipment in the mid-range T3 includes aircon, traction control, built-in phone, alloys, parking sensors, alarm, split-fold rear seats and excellent seat and steering column adjustment.

Pay about Â£10,200 for a '12 12-reg T3, Â£13,600 for an '14 14-reg T-Spirit, or Â£15,500 for a '13 63-reg Plug-in T-Spirit.